Sofa



FIG. 1 is a top, front and side perspective view of a sofa showing my new design;

FIG. 2 is a top, plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right elevational view, the left side being a mirror image thereof; and,

FIG. 5 is a front elevational view thereof. 

The ornamental design for a sofa, as shown and described. 